it also excludes modelling terrains through bryce's native creator and so on That seems kind of extraordinary. I can see not using preset skies, atmospheres etc., but most programs generate terrain heightmaps randomly from mathematical formula. Did they specify just Bryce terrain, or did they name all terrain generators? I have several programs that make terrain from heightmaps - Leveller, Geofrac, Terragen, Carrara Studio, Metasequioa - not to mention Photoshop filters. Are all of those banned as well as Bryce? I'm not entering the competition, so it doesn't matter to me, but it seems a bit odd to ban terrains generated from mathematical formulae. Doesn't Mojoworld do the same thing? And what about programs like Universe that (I think) randomly generate starfields. Huh? Huh?